Assign a fortune to little Albert (5)
I believe the answer is:
allot
'assign' is the definition.
('allot' can be a synonym of 'assign')
'a fortune to little albert' is the wordplay.
'a fortune' becomes 'lot' ('lot' can be a synonym of 'fortune').
'to' says to put letters next to each other (I've seen this in other clues).
'little albert' becomes 'al' (short form of the name).
'lot' put after 'al' is 'ALLOT'.
(Other definitions for allot that I've seen before include "Distribute in portions" , "Give, apportion" , "Assign or distribute" , "Apportion (something to someone)" , "Apportion, share" .)